There is an increasing need for long term observation of the earth-ocean system. In particular, scientists wish to monitor oceanic processes as well as improve predictive modeling of complex natural phenomena that vary over distance and time. Ocean observatories are being deployed at the seafloor and connected by cable or buoy to surface networks to help scientists study these oceanic processes. Scientists are also deploying unmanned underwater vehicles (UUV) that, due to their mobility, can expand the reach of the seafloor observatories. These UUVs typically carry sensors on-board and operate autonomously, carrying out pre-programmed missions. Certain types of UUVs are tethered by cable to the seafloor observatories. The tethered UUVs have a short range of motion and are limited by the length of the tether. Scientists are also deploying un-tethered UUVs which are controlled wirelessly by an acoustic communication system or an optical communication system. Acoustic communication systems, however, are limited by low bandwidth and high latency, and do not permit video or other high-rate data transfers.
Accordingly, there is a need for an improved underwater communication system that allows high-bandwidth, bidirectional wireless communication between UUV and seafloor observatories or other seafloor nodes. In general, there is a need for a high-bandwidth, high-range underwater communication system that allows bidirectional wireless communication.